HTTP URL Mapping
  

allows you define the HTTP URL mapping if your FTP server has HTTP access. after done this, you can use the "Copy HTTP URL" feature to get the http url with the folders/filed selected.

HTTP URL
the HTTP root path, for example your website is 'http://www.abc.com', then it is 'http://www.abc.com',


FTP Web Root Path
the FTP root path of yours. for example "/user/home/~yourname" or "/"


Examples:
you have a file at your FTP root path named 'index.htm'.
the FTP full path of 'index.htm' is /user/index.htm
the web full path of 'index.htm' is http://www.test.com/index.htm
then
HTTP URL is: http://www.test.com
FTP Web Root Path is: /user